- Email: [email protected]
Radial artery approach for outpatient peripheral arteriography
598
CLINICAL RADIOLOGY
Fig. 2
Fig. 1
TRUE MASSIVE THYMIC H Y P E R P L A S I A SIR We read with interest the recent case report 'True Massive Thymic Hyperplasia' [1]. We have recently encountered a similar case in our practice which illustrates some features which are unusual in thymic hyperplasia. The radiograph (Fig. 1) is that of a 13-week-old child following emergency admission with respiratory difficulties after several weeks of periods when the child appeared to struggle for breath. The child had sternal recession during inspiration but otherwise the examination was unremarkable and oxygen saturation was normal on air. The child had been ventilated following birth at 37 weeks for respiratory distress syndrome and in addition had been admitted at the age of 4 weeks with confirmed bronchiolitis. The chest radiograph shows widening of the superior mediastinum in addition to the more characteristic right sided thymic 'sail sign' distinguishing the normal thymic outline. A C T scan was performed in order to characterise the mediastinal lesion (Figures 2 & 3). This demonstrates a homogenously enhancing anterosuperior mass extending posteriorally with the right brachiocephalic vein displaced laterally and the left brachiocephalic vein displaced inferiorally down to the level of the carina. The tumour which weighed 54 g was resected surgically at which time the right brachiocephalic vein was described as being stretched across the lateral aspect of the turnout like a bow string. Histological examination demonstrated entirely normal thymic tissue. The patient has remained well and is asymptomatic following discharge. The described case appears to be a good example of rebound thymic hyperplasia secondary to the stresses of hyaline membrane disease followed by an episode of bronchiolitis. It demonstrates not only the diagnostic difficulty caused by thymic hyperplasia but the additional problems posed by a symptomatic ectopic thymus causing significant displacement of normal mediastinal structures. Ectopic thymic tissue which may be continuous with or separated from normal thymus has been described in a variety of positions in the mediastinum. Thymic enlargement alone uncommonly results in respiratory symptoms, however, symptoms are more likely to arise in glands which are abnormally positioned [2,3]. Biopsy is advocated in symptomatic cases showing evidence of vascular or airway compression [3]. - -
J. S. GREEN A. R. RICKETT
Department of Clinical Radiology Leicester Royal Infirmary Leicester LE1 5 W W
Fig. 3
References
1 0 b a r o RO. Case report: True Massive Thymic Hyperplasia. Clinical Radiology 1996;51:62 64. 2 Swischuk LE. Imaging of the Newborn, Infant and Young Child, 3rd ed. Baltimore: Williams and Wilkins, 1989:18-26. 3 Silverman FN, Kuhn JP. Caffey's Pediatric X-Ray Diagnosis, 9th ed. St Louis: Mosby, 1993:651 658.
R A D I A L ARTERY A P P R O A C H F O R O U T P A T I E N T PERIPHERAL ARTERIOGRAPHY
SIR I welcomed the paper 'Radial Artery Approach for Outpatient Peripheral Arteriography' [1] and would like to comment. I would agree that the procedure is preferable to the trans-brachial or trans-axillary route and is technically only slightly more difficult to learn. In my small series of 18 cases to date, all were for coronary arteriography or peripheral arteriography where routine femoral access was - -
© 1996 The Royal Collegeof Radiologists, ClinicalRadiology, 51, 597-599.
CORRESPONDENCE contraindicated or h a d failed. I have had doubts about the ethics of using radial access routinely when there is no contraindication to the femoral approach, as there is theoretically an increased risk of stroke when crossing the left vertebral artery origin and manipulating within the ascending aorta. Indeed a relatively recent paper [2] recorded two post-operative strokes in a series of 100 coronary arteriograms performed via the radial route. Stroke is a recognized and fortunately rare complication of coronary angiography but if this 2% risk is also applicable to peripheral arteriograms by this route then the patients should be informed of this prior to consent and the available alternative approaches described. I suspect that if care is taken to avoid inadvertent and repeated catheterisation of the vertebral artery (a factor sited in one of the two quoted strokes), then the risk is significantly diminished. A larger series is needed to confirm this and I am approaching our Ethics Committee with this in mind; a multi-centre study would be quicker! Regarding the Allen test, I have used both this and the pulse oximeter technique and in the admittedly small n u m b e r of 18 cases, there has been no discrepancy, though four patients had a unilateral positive test necessitating use of the other side. Using the pulse oximeter I place the probe first on the index finger and then the middle finger, compressing the radial artery whilst watching for pulsatile flow on the trace. Loss of pulsatile trace on radial compression implies insufficient ulnar flow. I have no experience of Tolazoline as it is contraindicated in coronary artery disease, but I routinely give intra-arterial Nitronal 500 m g in 5 ml on removing the dilator from the sheath and a further similar dose before removing the sheath. Spasm has not been a problem. Finally, I would like to know if the authors have experience of repeat studies by the radial route: m y one attempt was unsuccessful as the wire failed to pass. N. L L O Y D BISHOP
Royal Sussex County Hospital Eastern Road Brighton BN2 5BE
References
1 A1-Kutoubi A, De Jode M, Gibson M. Radial artery approach for outpatient peripheral arteriography. Clinical Radiology 1966;51:110112. 2 Lotan C, Hasin' Y, Mosseri M e t al. Transradial approach for coronary angiography and angioplasty. American Journal of Cardiology 1995;76:164-167.
SIR - We thank D r Bishop for his observations a n d would like to respond to the points he made. (1) The risk of stroke is not peculiar to a radial artery approach but is c o m m o n to all arteriography from upper limb approach, as well as arch studies by the femoral route. We not that the cerebral event in one of the patients mentioned in the recent report sited by Dr Bishop [1] was not related to catheterisation. Moreover, in his comprehensive report on complications of angiography A b r a m s [2] indicates an incidence of cerebral embolism from the brachial route of only 0.09% in a large series of 24 124 patients. In our series of approximately 140 patients to date we have not encountered this complication. We do, however, concur with the call for caution to avoid manipulation of wires and catheters in the vertebral arteries. (2) We accept that pulse oximetry m a y be used for assessment of supply to the hand but find the Allen test easier to perform and document.
© 1996 The Royal College of Radiologists, ClinicalRadiology, 51, 597 599.
(3)
(4)
599
Interestingly, a quick, and admittedly unscientific poll of anaesthetists in our and neighbouring institutions revealed that most anaesthetists did not even bother to test for this before they placed radial artery lines. We have used Tolazoline in peripheral angioplasty for m a n y years and hence our preference for its use in the radial route. Recently however we have been using 400 m c g Isosorbide dinitrate instead as it causes less irritation. We do inject the vaso dilator in the axillary artery as injecting close to the h a n d can be extremely painful. We have performed angiography by the radial route on several occasions following arterial line insertion by an anaesthetist and on two occasions following previous arteriography through the same route with success in most cases.
A. A L - K U T O U B I M. D E J O D E M. G I B S O N
Radiology Department St Mary's Hospital London W2 1NY
References
1 Lotan C, Hasin Y, Mosseri M et al. Transradial approach for coronary angiography and angioplasty. Amereian Journal of Cardiology 1995;76:164-167. 2 A b r a m s HL. Compilations of coronary arteriography. In Abrams H L ed. Abrams Angiography, Vascular and Interventional Radiology, 3rd ed. Boston: Little Brown and Co, 1983:503-518.
F E M O - S T O P 11 S Y S T E M F E M O R A L C O M P R E S S I O N A R C H SIR - We would like to draw colleagues attention to two potentially serious sequelae associated with the use of Femo-Stop II System Femoral Compression Arch ( R A D I Medical Systems AB, Uppsala, Sweden). This device is used for controlled pneumatic compression of femoral arteries after femoral angiography. It has obvious labour-saving advantages and was used to great effect in this hospital in 1994. In 1995, the company modified the manufacture by changing the belt from canvas to a paper based design. The inflation p u m p was also modified so that when inflated the broadest point on the new device is narrower than on the initial design. When looping the belt through the arch, the teeth on the jaws of the device must be firmly compressed and closed. Meticulous care must be taken when doing this otherwise the arch and inflated p u m p m a y slip off the puncture site with significant consequences. This was not a problem with the original design and is not clearly pointed out in the literature supplied with the device. The narrow base of the inflated p u m p also has the effect of causing a tendency to slip off the puncture site. Again this was not a feature of the previous design. A third, less significant problem is the fact that the deflated p u m p in the new modification has a tendency to crinkle which can nip the patients' skin as the device is being removed. We came to our conclusions regarding this device independently. The design modifications leave a tot to be desired by comparison with the original product. E. B R E S N I H A N P. M c C A R T H Y
Academic Department of Radiology University College Hospital Galway
CLINICAL RADIOLOGY
Fig. 2
Fig. 1
TRUE MASSIVE THYMIC H Y P E R P L A S I A SIR We read with interest the recent case report 'True Massive Thymic Hyperplasia' [1]. We have recently encountered a similar case in our practice which illustrates some features which are unusual in thymic hyperplasia. The radiograph (Fig. 1) is that of a 13-week-old child following emergency admission with respiratory difficulties after several weeks of periods when the child appeared to struggle for breath. The child had sternal recession during inspiration but otherwise the examination was unremarkable and oxygen saturation was normal on air. The child had been ventilated following birth at 37 weeks for respiratory distress syndrome and in addition had been admitted at the age of 4 weeks with confirmed bronchiolitis. The chest radiograph shows widening of the superior mediastinum in addition to the more characteristic right sided thymic 'sail sign' distinguishing the normal thymic outline. A C T scan was performed in order to characterise the mediastinal lesion (Figures 2 & 3). This demonstrates a homogenously enhancing anterosuperior mass extending posteriorally with the right brachiocephalic vein displaced laterally and the left brachiocephalic vein displaced inferiorally down to the level of the carina. The tumour which weighed 54 g was resected surgically at which time the right brachiocephalic vein was described as being stretched across the lateral aspect of the turnout like a bow string. Histological examination demonstrated entirely normal thymic tissue. The patient has remained well and is asymptomatic following discharge. The described case appears to be a good example of rebound thymic hyperplasia secondary to the stresses of hyaline membrane disease followed by an episode of bronchiolitis. It demonstrates not only the diagnostic difficulty caused by thymic hyperplasia but the additional problems posed by a symptomatic ectopic thymus causing significant displacement of normal mediastinal structures. Ectopic thymic tissue which may be continuous with or separated from normal thymus has been described in a variety of positions in the mediastinum. Thymic enlargement alone uncommonly results in respiratory symptoms, however, symptoms are more likely to arise in glands which are abnormally positioned [2,3]. Biopsy is advocated in symptomatic cases showing evidence of vascular or airway compression [3]. - -
J. S. GREEN A. R. RICKETT
Department of Clinical Radiology Leicester Royal Infirmary Leicester LE1 5 W W
Fig. 3
References
1 0 b a r o RO. Case report: True Massive Thymic Hyperplasia. Clinical Radiology 1996;51:62 64. 2 Swischuk LE. Imaging of the Newborn, Infant and Young Child, 3rd ed. Baltimore: Williams and Wilkins, 1989:18-26. 3 Silverman FN, Kuhn JP. Caffey's Pediatric X-Ray Diagnosis, 9th ed. St Louis: Mosby, 1993:651 658.
R A D I A L ARTERY A P P R O A C H F O R O U T P A T I E N T PERIPHERAL ARTERIOGRAPHY
SIR I welcomed the paper 'Radial Artery Approach for Outpatient Peripheral Arteriography' [1] and would like to comment. I would agree that the procedure is preferable to the trans-brachial or trans-axillary route and is technically only slightly more difficult to learn. In my small series of 18 cases to date, all were for coronary arteriography or peripheral arteriography where routine femoral access was - -
© 1996 The Royal Collegeof Radiologists, ClinicalRadiology, 51, 597-599.
CORRESPONDENCE contraindicated or h a d failed. I have had doubts about the ethics of using radial access routinely when there is no contraindication to the femoral approach, as there is theoretically an increased risk of stroke when crossing the left vertebral artery origin and manipulating within the ascending aorta. Indeed a relatively recent paper [2] recorded two post-operative strokes in a series of 100 coronary arteriograms performed via the radial route. Stroke is a recognized and fortunately rare complication of coronary angiography but if this 2% risk is also applicable to peripheral arteriograms by this route then the patients should be informed of this prior to consent and the available alternative approaches described. I suspect that if care is taken to avoid inadvertent and repeated catheterisation of the vertebral artery (a factor sited in one of the two quoted strokes), then the risk is significantly diminished. A larger series is needed to confirm this and I am approaching our Ethics Committee with this in mind; a multi-centre study would be quicker! Regarding the Allen test, I have used both this and the pulse oximeter technique and in the admittedly small n u m b e r of 18 cases, there has been no discrepancy, though four patients had a unilateral positive test necessitating use of the other side. Using the pulse oximeter I place the probe first on the index finger and then the middle finger, compressing the radial artery whilst watching for pulsatile flow on the trace. Loss of pulsatile trace on radial compression implies insufficient ulnar flow. I have no experience of Tolazoline as it is contraindicated in coronary artery disease, but I routinely give intra-arterial Nitronal 500 m g in 5 ml on removing the dilator from the sheath and a further similar dose before removing the sheath. Spasm has not been a problem. Finally, I would like to know if the authors have experience of repeat studies by the radial route: m y one attempt was unsuccessful as the wire failed to pass. N. L L O Y D BISHOP
Royal Sussex County Hospital Eastern Road Brighton BN2 5BE
References
1 A1-Kutoubi A, De Jode M, Gibson M. Radial artery approach for outpatient peripheral arteriography. Clinical Radiology 1966;51:110112. 2 Lotan C, Hasin' Y, Mosseri M e t al. Transradial approach for coronary angiography and angioplasty. American Journal of Cardiology 1995;76:164-167.
SIR - We thank D r Bishop for his observations a n d would like to respond to the points he made. (1) The risk of stroke is not peculiar to a radial artery approach but is c o m m o n to all arteriography from upper limb approach, as well as arch studies by the femoral route. We not that the cerebral event in one of the patients mentioned in the recent report sited by Dr Bishop [1] was not related to catheterisation. Moreover, in his comprehensive report on complications of angiography A b r a m s [2] indicates an incidence of cerebral embolism from the brachial route of only 0.09% in a large series of 24 124 patients. In our series of approximately 140 patients to date we have not encountered this complication. We do, however, concur with the call for caution to avoid manipulation of wires and catheters in the vertebral arteries. (2) We accept that pulse oximetry m a y be used for assessment of supply to the hand but find the Allen test easier to perform and document.
© 1996 The Royal College of Radiologists, ClinicalRadiology, 51, 597 599.
(3)
(4)
599
Interestingly, a quick, and admittedly unscientific poll of anaesthetists in our and neighbouring institutions revealed that most anaesthetists did not even bother to test for this before they placed radial artery lines. We have used Tolazoline in peripheral angioplasty for m a n y years and hence our preference for its use in the radial route. Recently however we have been using 400 m c g Isosorbide dinitrate instead as it causes less irritation. We do inject the vaso dilator in the axillary artery as injecting close to the h a n d can be extremely painful. We have performed angiography by the radial route on several occasions following arterial line insertion by an anaesthetist and on two occasions following previous arteriography through the same route with success in most cases.
A. A L - K U T O U B I M. D E J O D E M. G I B S O N
Radiology Department St Mary's Hospital London W2 1NY
References
1 Lotan C, Hasin Y, Mosseri M et al. Transradial approach for coronary angiography and angioplasty. Amereian Journal of Cardiology 1995;76:164-167. 2 A b r a m s HL. Compilations of coronary arteriography. In Abrams H L ed. Abrams Angiography, Vascular and Interventional Radiology, 3rd ed. Boston: Little Brown and Co, 1983:503-518.
F E M O - S T O P 11 S Y S T E M F E M O R A L C O M P R E S S I O N A R C H SIR - We would like to draw colleagues attention to two potentially serious sequelae associated with the use of Femo-Stop II System Femoral Compression Arch ( R A D I Medical Systems AB, Uppsala, Sweden). This device is used for controlled pneumatic compression of femoral arteries after femoral angiography. It has obvious labour-saving advantages and was used to great effect in this hospital in 1994. In 1995, the company modified the manufacture by changing the belt from canvas to a paper based design. The inflation p u m p was also modified so that when inflated the broadest point on the new device is narrower than on the initial design. When looping the belt through the arch, the teeth on the jaws of the device must be firmly compressed and closed. Meticulous care must be taken when doing this otherwise the arch and inflated p u m p m a y slip off the puncture site with significant consequences. This was not a problem with the original design and is not clearly pointed out in the literature supplied with the device. The narrow base of the inflated p u m p also has the effect of causing a tendency to slip off the puncture site. Again this was not a feature of the previous design. A third, less significant problem is the fact that the deflated p u m p in the new modification has a tendency to crinkle which can nip the patients' skin as the device is being removed. We came to our conclusions regarding this device independently. The design modifications leave a tot to be desired by comparison with the original product. E. B R E S N I H A N P. M c C A R T H Y
Academic Department of Radiology University College Hospital Galway